It's eight o'clock, Friday morning, and the night shifters are emerging from the Pike River coal mine. One, James O'Donoghue, remarks on the gas problems they'd been having overnight.

This will be a long day. A very long day.

Two climb free

Mid-afternoon, about 3.30pm, and a miner in his early 20s, leaves his friends behind to walk out of the long tunnel. He's knocking off early.

He doesn't know that mere minutes later - or at least this is what most evidence seems to suggest - the power cuts out.

The ventilators, which would usually blow the cold, fresh air through like a gale, whine to a stop. And this is not the first time it's happened.

It's quiet. The air is dense, the heat rising.

3.45pm. Electrician Russell Smith, 50, is entering the mine through the 2km long entrance tunnel, when the gas explodes. He keeps going.

Continuing down the tunnel, he finds a mechanical loader. Its driver, 24-year-old Daniel Rockhouse is nearby. The blast had knocked him clean from his machine, hurting him - but not badly.

There are two escape options: the long walk back down the entrance tunnel, or a walk to the nearest ventilation shaft then a formidable 108-metre climb up the ladder. If there is another blast, they're in trouble either way. They choose the ladder.

Police called

Above the ground, a telephone rings. It is 4.15pm, and there is a static-laden voice at the other end of the line. It's one of the miners, far beneath the ground. Somehow, he's got a signal out.

Something has gone wrong. There are people trapped.

There are, says Pike River chief executive Peter Whittall, 36 name tags hanging on the wall. That spells 36 missing men - half of them miners, half contractors like engineers.

Mine managers call the police.

Rumours start

Two men stumble out of the bush. It's the electrician and the injured loader driver.

Rumours swirl. Smith and Rockhouse say they had heard three men following up the shaft behind them. Other reports claim a body has been brought out.

The number of men unaccounted for drops from 36 to 31, then down to 27, then climbs again to 29.

In the nearby township of Runanga, the partner of 60-year-old Alan Dixon says she received a call from the phone in the mine, after the explosion.

"It was quite fuzzy," says Dixon's son, Joel.

Police are dubious - but they have confirmed the one call after the blast.

Rescuers can be confident of one thing: at least some of the men survived the blast.

Whether they can survive the continued build-up of methane gas is another question.

Talk is easy but facts are scarce.

Rockhouse knows one thing for sure, though: his younger brother Ben is still in the mine.

Daniel Rockhouse has left his cellphone behind in the mine. Family repeatedly dial the number - but no one is answering.

Media arrives

Rescuers, police and fire services gather at the mine entrance, but nobody can go in yet. As rumours spread rapidly up and down the West Coast, family and friends begin arriving at the mine.

They are gently turned away; told to wait back in Greymouth at the Red Cross Hall.

Ali, a business owner, says the town immediately knew there was a disaster when helicopters roared overhead.

Living on the West Coast meant knowing in the back of your mind that tragedy could strike anytime, she said.

"But Coasters are tough. We're a tough little tight-knit community."

The media arrives, a couple of choppers hovering high above the mine entrance until Civil Aviation imposes a no-fly zone at the request of police. Locals are glued to their radio and television sets, as a frayed-looking Whittall fronts up to the cameras.

He knows the mine. He knows the miners. He has many sleepless hours ahead of him.

Rescuers congregate in the utes and buildings outside the mine entrance, but nobody will be entering tonight.

Once they would have used canaries to test the air quality in the mine. If they canary keeled over, it was time to get to the surface.

They don't have canaries now, but they still suspect the methane and carbon monoxide gases are lingering in clouds throughout the mine. And 29 missing men is enough. They do not need to risk the rescuers.

They hunker down for the night.

Worse scenario

It's Saturday morning, raining and overcast.

In Runanga, store owner Gerry McMillan says he and his customers are holding on to hope. Not so many customers, though. Several of his regulars are among the missing.

One of the miners' girlfriends had rung him at 1am asking for a bottle of coke because she could not sleep.

"She was very distraught," he says. "She came in this morning to pick up a pack of smokes before heading to her family in Dobson."

Operating theatres and funeral directors have both been put on stand-by in a town nervously awaiting news of 29 of its men trapped in a coal mine.

At the local hospital, 50 beds were cleared in anticipation of the men being pulled out. Specialists for burn injuries and respiratory problems, as well as extra ventilators, were brought in.

But also prepared for the worse scenario were funeral directors. Derek Cone, from Westland Funerals Services, was put on 24-hour standby.

"We're feeling sad for everybody and wondering just like everyone else, but we're also here to attend to people's needs and care for them," Cone says.

Their job is more than running funerals - it is also helping grieving families cope. "We just have to react to what happens," he says.

Around town, locals say they had been listening to every report in hope, yet they were at the same time reluctant to probe each other.

One Coaster says the accident had immediately made her think of her father, who had died in a mine years earlier.

"It brings it all back," she says. "It's like we're shell shocked. There's nothing to be said."

Retiree Myrtle Sowerby says she is simply glad her children decided against careers in mining. "It's just too dangerous," she says. "It's pretty sad, alright. I just hope they make it out like they did in Chile."

A local man who works at another mine, nearby, says he too is absolutely gutted. Of course he is.

"But it's part of it," he adds. "You go to work and you don't know if you're going to come home."

Sombre day

At one Greymouth hotel, it's quiet. There are drinkers - but they're quiet drinkers.

It's been a sombre day, says the publican.

"Everybody knows somebody. I have seen family and friends of the miners come in all day - just stunned by what has happened," he says.

"I have seen grown men crying today, at least 20. I mean, we have all stood in the bar and had fights but, at the end of the day, this is heart-wrenching.

"The miners are a very close knit workforce.

"I mean. these guys drink with me a lot. I know a lot about Pike River."

Can you tell us?

"No, not yet. Look, the community is hurting. That's all I have to say."

- Reporting team: Michael Dickison, Abby Gillies, Carolyne Meng-Yee, Matt Kersten, Jonathan Milne